The political weblog Daily Kos (DK) was launched on May 26, 2002 by its founder, Markos Moulitsas Zúniga, who continues to maintain the site from his Berkeley, California residence. “Kos” is pronounced “kose,” like the second syllable of Zúniga's first name. Over the course of its first year, DK attracted more than 1.6 million unique visits and about 3 million total page views. Since then, its traffic has grown exponentially. In June 2014 alone, for instance, the site drew more than 6.4 million unique visitors, 16.3 million total visits, and 37 million page views.

In November 2004, Zúniga described DK as a “Democratic” and “partisan” blog with just “one goal in mind: electoral victory” for the Democrats. “Recogniz[ing] that Democrats run from left to right on the ideological spectrum,” added Zúniga, Daily Kos “happily embrace[s] centrists like NDN's Simon Rosenberg and Howard Dean, conservatives like Brad Carson and Martin Frost, and liberals like John Kerry and Barack Obama.”

DK's unwavering allegiance to the Democratic Party was on full display in 2004, when the site raised some $500,000 for 15 Democrat candidates whose campaigns were in need of financial support. Two years later, using the online fundraising political action committee ActBlue, DK raised another $1.4 million for 17 Democrats.

Zúniga and a small group of select contributors post directly to DK's front page each day. Apart from this, most of the site's content appears in its “diaries”—entries written by registered users who are limited to two postings per day. The titles of these diary entries are listed in the right-hand column of the front page, in reverse chronological order. Those that are highly recommended by DK's so-called “trusted users” are granted longer display times. Popular or controversial diaries commonly elicit hundreds and even thousands of reader comments.

DK's front-page posts and diary entries often consist of excerpts from news stories from outside sources, interspersed with commentary by the author of each post or diary. Some posts are “open threads,” which invite readers to comment on any issue they wish to address. And occasionally there are “live threads” of commentary on significant events—such as debates or elections—as they happen in real time.

According to DK, nearly all of its contributors are “ordinary citizens interested in talking about and participating in the political process.” Most of them “fall on the liberal side of the U.S. political spectrum,” though “people of conservative views are welcome to come and debate.”

DK currently subdivides its front-page posts into four main subject categories:

(1) The Labor category contains posts that typically: promote unionization; contend that tax cuts for “those at the top” mean “less money for road repairs … medical research and ... schools”; favor an increase in the minimum wage; claim (falsely) that female employees are paid less than equally qualified and credentialed males; allege that “systemic racism” pervades the American workplace; condemn “income and wealth inequality”; demand paid sick leave for all workers; and depict corporations as heartless entities that “care more about profit than about workers' lives.”

(3) The Elections category focuses on various political candidates and races across the United States—always with a preference for Democrats and progressives.

(4) The Economics category features posts that routinely: praise the virtues of wealth redistribution, progressive taxation, and massive government expenditures on infrastructure and social-welfare programs; portray Republicans as doing “everything they can to deliver for corporate America at the expense of the American people”; and depict the U.S. as a nation where “the growing concentration of wealth,” coupled with “a significant reduction in taxes” on the rich, “has meant less money to spend on investments for the public good, like education and the protection of children.”

In April 2004, DK initiated dKosopedia, which it describes as “a collaborative project of the DailyKos community.” Modeled after Wikipedia, this “political encyclopedia” is “written from a left/progressive/liberal/Democratic point of view while also attempting to fairly acknowledge the other side's take.” All DK readers are invited to contribute to dKosopedia, which, as early January 2015, contained more than 14,300 articles.